source: downloads/openal-0.0.8/src/audioconvert/audioconvert.h @ 17

/* -*- mode: C; tab-width:8; c-basic-offset:8 -*-
 * vi:set ts=8:
 *
 * This is the header that apps should include when linking against
 * audioconvert or such.
 */
#ifndef AC_H_
#define AC_H_

#include "al_siteconfig.h"

#include <AL/al.h>

#include "audioconvert/ac_adpcm.h"

/* new data types */
typedef struct _acAudioCVT {
        int needed;                     /* Set to 1 if conversion possible */
        ALushort src_format;            /* Source audio format */
        ALushort dst_format;            /* Target audio format */
        double rate_incr;               /* Rate conversion increment */
        void   *buf;                    /* Buffer to hold entire audio data */
        int    len;                     /* Length of original audio buffer */
        int    len_cvt;                 /* Length of converted audio buffer */
        int    len_mult;                /* buffer must be len*len_mult big */
        double len_ratio;       /* Given len, final size is len*len_ratio */
        void (*filters[10])(struct _acAudioCVT *cvt, ALushort format);
        int filter_index;               /* Current audio conversion function */
} acAudioCVT;

/* Audio format flags (defaults to LSB byte order) */
#define AUDIO_U8        0x0008  /* Unsigned 8-bit samples */
#define AUDIO_S8        0x8008  /* Signed 8-bit samples */
#define AUDIO_U16LSB    0x0010  /* Unsigned 16-bit samples */
#define AUDIO_S16LSB    0x8010  /* Signed 16-bit samples */
#define AUDIO_U16MSB    0x1010  /* As above, but big-endian byte order */
#define AUDIO_S16MSB    0x9010  /* As above, but big-endian byte order */

/* Native audio byte ordering */
#ifndef WORDS_BIGENDIAN
#define AUDIO_U16       AUDIO_U16LSB
#define AUDIO_S16       AUDIO_S16LSB
#else
#define AUDIO_U16       AUDIO_U16MSB
#define AUDIO_S16       AUDIO_S16MSB
#endif

/* macros */
#define acFormatBits(fmt)           (fmt & 0xff)

/* bit changes */
void acConvert16MSB(acAudioCVT *cvt, ALushort format);
void acConvert16LSB(acAudioCVT *cvt, ALushort format);
void acConvert8(acAudioCVT *cvt, ALushort format);

/* frequency changes */
void acFreqMUL2(acAudioCVT *cvt, ALushort format);
void acFreqDIV2(acAudioCVT *cvt, ALushort format);
void acFreqSLOW(acAudioCVT *cvt, ALushort format);

/* channel changes */
void acConvertStereo(acAudioCVT *cvt, ALushort format);
void acConvertMono(acAudioCVT *cvt, ALushort format);

/* misc */
int   ac_is_wave(void *data);
void *ac_guess_info(void *data, ALuint *size,
                ALushort *fmt, ALushort *channels, ALushort *freq);
void *ac_guess_wave_info(void *data, ALuint *size,
                ALushort *fmt, ALushort *channels, ALushort *freq);
void *ac_wave_to_pcm(const void *data, ALuint *size,
                ALushort *fmt, ALushort *channels, ALushort *freq);

int ac_isWAVE_ANY_adpcm(void *datap, ALuint size);
int ac_isWAVE_IMA_adpcm(void *data, ALuint size);
int ac_isWAVE_MS_adpcm(void *data, ALuint size);
void *ac_getWAVEadpcm_info(void *data, ALuint *size, void *spec);

/* sdl helper stuff */
int acBuildAudioCVT(acAudioCVT *cvt,
        ALushort src_format, ALubyte src_channels, ALuint src_rate,
        ALushort dst_format, ALubyte dst_channels, ALuint dst_rate);

int acConvertAudio(acAudioCVT *);
void *acLoadWAV(const void *data, ALuint *size, void **udata,
                ALushort *format,
                ALushort *channels,
                ALushort *freq);

#endif /* AC_H_ */